a strange piece

We went to mimi’s cafe in here in Salt lake city for my father’s day brunch and I came across this in their lobby. Looks pretty old. Imbeded in the top are chip sharpened rocks in rows, near the end are a couple iron rods looped back into the top. As you can see the right side has been sawn to a slope. I’ve been there on multiple occasions for years and never noticed it. Everyone was in a hurry to leave so I didn’t have much time to look. Anyone know what it is? I asked the hostess but she had no idea.

Thank you joe, I had to wiki. There it said they are still used to this day in one form or another.It looks as this one is has been turned into a table. It is used to seperate grain and stock by being dragged by livestock in circles and figure eights over the harvest piles.